It has been reported that autoimmune hepatitis is induced by the drastic change of sex hormone, such as pregnancy and menopause. However, its pathogenic mechanism is not well-known. In this study, we focused on the hepatic dendritic cells. We used the mouse model of autoimmune hepatitis to investigate the effect of the autologous reactivity of estrogen. As a result, it was shown that the autoimmune liver injury of the mice was inhibited by the administration of estrogen. At the same time, the number of CD274+ immature dendritic cells was increased in the liver of those autoimmune hepatitis mice. Moreover only these dendritic cells showed the elevated ability to produce IL-10. At the same time they indicated the decreased serum level of IL-12. These results suggested that the inhibitory dendritic cells, which were increased in the liver by estrogen exposure, suppressed the autoimmune liver injury.